While it isn't compulsory to read through this, I would advise that everyone does so... Firstly, as it will answer some questions about certain terminology used within this roleplay, and secondly it will allow you to tell me if there is anything you don't understand so I can help you.

.: Keepers :.
Said to be superior to anything else alive, the Keepers are humans with exceptional powers. While for the most part they have similar physical attributes, such as being able to lift thousands of tonnes alone or flying around the speed of a few thousand miles an hour, much differentiates Keepers from each other. This is mostly thanks to the Dragon Soul they Keep, as the individual Dragon's strengths and weaknesses are passed on. The King of the Dragons, Rayne, for example, gives more strength and speed than any other Dragon, and he bestows control over black fire and crimson lightning, while his Keeper will not gain anywhere near as much damage absorbtion as the other Keepers.
Keepers are chosen either at birth or during a traumatic event. The reasons behind being chosen is unclear, although it is believed that it's something to do with the strength of your soul. If you are born with a strong soul, which shows the strength of your will, or when you are faced with an event which would normally leave you without a will to live, which shows your soul's strength, then a Dragon is likely to choose you as their next Keeper. The weapons of Keepers are mostly tied to that of the personality of the Dragon, much like their power. A strong and stout Dragon would bestow an axe, for example.

.: Dragons :.
Possibly the strongest stand-alone race to ever grace the land and skies, Dragons ruled over all. While they were hated by humanity, they retained an honourable composure, never killing any human that didn't directly attack them. They have an intelligence, but it works differently to our own: they have no logic, but their decisions are guided by how well the choice suits them and their group. The weak are expendable, and are expected to sacrifice themselves for the sake of the stronger. Aside from their beliefs, they have no set hierachy within the race. It is like most feral races, where dominance is attained through defeating the strongest of your number.
There was never a definite number of Dragons, but it is known that Dragons are immortal. They cannot die outside of battle, and they do not grow old: only stronger. As a side-effect of this, there are few births, and young Dragons are a special rarity. It is believed that there were over 30'000 upon the start of the Forgotten War, and none survived. It was only thanks to the Keepers of their souls that they still live, albeit as a second conscious: a mere shadow of their past. Dragons are able to take control of their Keepers body, but many have grown complacant and only do so upon getting permission. The rare instances that they do this compulsively is when their Keeper is either hopeless in battle, or in mortal danger. This means that when a Dragon takes command of the human's body they remove the blocks they put on their Keeper's power to prevent anything dangerous happening, which allows them to fight with greater strength that the original Keeper could.

.: False Keepers :.
There is a lot of things that seperates a Keeper and a False Keeper. The most obvious is that the latter does not take on the soul of a Dragon, therefore leading the relationship between Human and Dragon to become shaky at best. False Keepers gain none of the physical boosts in speed or strength, nor do they possess the ability to fly. They are merely humans with the ability to use the magical powers of a Dragon. The reasons behind this are unclear, although many link it back to when Rayne imprisoned the rogue Dragons who felt that it was below them to join the human's in battle. The battle that ensued was a further show of Rayne's might, as he pretty much dealt with all of them alone.
What False Keepers have in an advantage over Keepers, on the other hand is something that makes them more powerful than any Keeper, Alfie included, who hasn't formed an iron-tight bond with their Dragon. For a Keeper to access the full might of his Dragon, he has to earn the trust of his Dragon, something that can only be done by showing a just use of the power given to you. False Keepers have no such limit and, as such, have access to all the power a Dragon can hold. This not only makes them dangerous, but it is also a handle for the various countries given that these False Keepers are feasibly all that can defeat a Keeper.
The Inprisonment of the Dragons was an incredible event, and the last show of the combined power of the race of Dragons. Taking the unconscious bodies of the rouge Dragons, the most powerful of their kind sealed their souls inside that of stone, called Keeper Ore: what stone they used differed with each Dragon, but they were forced to exist as nothing more than a soul without a body. Unable to use their power while imprisoned, the Dragons spent the thousands of years trying to coerce humanity into wielding their power: seemingly to serve the Human. The true intent of the Dragons is unknown, but what is known is that they would do anything to enact revenge upon Rayne and his consorts.

.: AT-MS :.
First created and tested in 1979 by an Ingrid Swelter, the All Terrain Mechanised Suits, or AT-MSs for short, are large human-shaped machines that can range from ten feet to fifty feet in height. The carry a multitude of munitions, from simple gatling-gun placements to heat seeking missiles to various countermeasures that give protection against other AT-MSs. Most AT-MS types are given Latin names, to honour Ms. Swelter who loved the language with a passion.
They can vary in size and weight, not only dependant on the country of origin, but also the purpose it serves. Scout AT-MSs, for example, only need a single operator, and are built for speed rather than offense. Within battle they prove useless, as the more superior Bellator AT-MSs can eaily tear them apart. While it is unusual, there has been a recent growth of Ensis AT-MSs: smaller, lighter MSs which excel in passing defences and attacking with their large sword-like arms. They prove vastly harder to build, as the swordarms need to be quite heavier than the Mech itself, and as such there are fewer in the battlefield.
Recently, America completed production of the Ferrator AT-MS: considered the ultimate AT-MS. Weighing at over 5'000 tonnes, and packing over 10'000 heat seeking missles, the Ferrator is an incredible war machine. It's armour is incredibly thick, and has been proven to be able to absorb attacks from both Ensis and Bellator AT-MSs with ease. It's only seeming weakness is it is incredibly slow, and requires a large team of 20 men to pilot. Loss of even one man renders a large portion of the Mech useless.

.: Magic :.
Far removed from the wand-waving of Harry Potter or the incantations of Middle Earth, Magic is the ancient art of bending matter to one's will. A person's magical ability is tied to their control of their own emotions, as well as the strength of will to force matter to do as directed. Magic takes many forms: from simple control of fire to the expert control of illusions. The 5 elements are the main vent of magic for the Keepers, with the elements they are most proficient with reflecting their personality. There are other forms of magic, with the ability to alter perception, change your appearance, increase or decrease gravity, blind people with light or flood the area with darkness being most familiar. There are some more exotic abilities, such as the ability to traverse reality through mirrors, but they are far rarer. Unlike most videogames, rarity does not instantly mean that the power is more powerful.
Very few, if any at all, can sufficiently control more than 2 elements of magic, and those who try either become terribly weak in terms of the power they can exert, or become destroyed by the sheer amount of energy. Also unlike most videogames, there is no distinction between damage you can take and the toll of magic you can cast: both require energy... So a weakened Keeper isn't going to be able to cast much by way of powerful magic, even if they could control their emotions at the time, and exceptionally control the matter around them. Finally, Magic is the altering of matter to another substance you want or moving matter around... Creating matter is impossible, as is destroying it.

.: The Four :.
If the Keepers are the ultimate form of humanity, than these are the ultimate weapons. A sword, a hammer, a lance, and a bow. All four have travelled through mythology and legends for countless centuries, masquerading as Excalibur or the Kusanagi, Odin's Lance or the Amenonuhoko, Hephaestus's Hammer, Eros's Bow or Artemis's Bow. All four have unlimited power, forged to be the strongest anti-creation weapons in existence, which gives them the power to be the only way of destroying matter. Much like the weapons forged for Keepers, these are seemingly unbreakable, and are always as keen as the day they were made. Strongly magical, each is said to be able to destroy one of the four main races in an instant:

Sword - Excalibur - Only a Keeper can wield this weapon, and it is the ultimate weapon against Demons, killing them upon contact.

Bow - Artemis' Bow - Only a Human can wield this weapon, and it is the ultimate weapon against Dragons and Keepers.

Hammer - Hephaestus's Hammer - The ultimate Demonic weapon, this is capable of defeating even the strongest of Dragons with a single swipe.

Lance - Odin's Lance - The ultimate weapon for False Keepers, it has the ability to slay Keepers with incredible ease.

The whereabouts of these Four are unknown, even to the Dragons, and they are as feared as greatly as they are sought after. It is said that when the Four combine once more, the race of Dragons will be reborn. It is all that keeps the Dragons hopeful... All that drives them to help their Keeper as much as possible... The False Keepers are also after these weapons, as are the Governments of the World, but they are soley for greed: to the Keepers, finding the weapons is the least they can try to do to repay the Dragons that guide and protect them.

If there is a term you would like explained, please tell me and I will add the description here.